1. Field of the Invention
The present invention relates to a Radio Frequency Identification (RFID) tag and a construction site management system and management method using the same. More particularly, the invention relates to an RFID tag and a construction site management system and management method using the same for efficiently implementing product management until products manufactured at a factory, such as construction materials and equipment for installation, are used at a construction site, as well as work management when such products are used at the construction site.
2. Description of the Related Art
There are generally two types of information to manage at a construction site in relation to products, such as construction materials and equipment for installation. One is product management until products manufactured at a factory are carried to and used at a construction site, and the other is work management at the time when those products are used at the construction site.
Systems for work management at a construction site using RFID tags include the one described in Japanese Patent Application Laid-Open No. 2005-326965, for example. Japanese Patent Application Laid-Open No. 2005-326965 describes that RFID tags are attached to materials, tools, workers and the like to manage work status, such as progress of a process and workers' working status.
However, a single shared RFID tag as used in Japanese Patent Application Laid-Open No. 2005-326965 has problems of being unable to efficiently perform product and work management and also tending to cause management errors.
For example, one problem is that since not a single piece but multiple pieces of information are required for one product in work management, an RFID tag that has only one RFID function, as in Japanese Patent Application Laid-Open No. 2005-326965, cannot handle this. That is, in product management, one RFID tag can handle one product, whereas in work management, a number of managed points are required for one product. Taking a pipe as an example of such a product, a point at which the pipe is connected represents a managed point in work management. As at least both ends need to be coupled to other equipment and the like for one pipe, both of the ends of the pipe represent managed points. Likewise, a T-shaped pipe has three connecting points and hence three managed points.
In this case, while it is possible to associate the ID of one product with the IDs of its managed points and extract managed point IDs from the ID of one product, because it does not directly associate one piece of RFID information with one managed point ID, mistakes in extracting managed points can be caused. Alternatively, although it is also possible to attach an RFID tag to each managed point of one product for management independently of an RFID tag for product management, it is likely to cause a mistake of erroneously attaching an RFID tag that should be attached to another product to one of a number of managed points.
One task involved in product management is the task of matching management for checking whether the quantity and/or product numbers of products correspond with an invoice when products shipped from a factory are carried into a construction site. To check a large number of products delivered to the construction site in a small amount of time, it is required that a bunch of pipes, for example, loaded on a truck and the like be efficiently read by a reading device from a remote location at a material entrance of the construction site.
On the other hand, work management at the time the products are used at the construction site involves reference of information recorded on an RFID tag on each managed point of products and/or recording of work progress for each managed point. The reading device therefore needs to select and read only an RFID tag that is attached to one managed point that should be currently managed from among RFID tags that are attached to a number of adjacent managed points. In this case, as the distance of RFID tag reading increases, the possibility arises that information on another managed point is also read.
As outlined above, RFID tags used for management of a construction site need to provide different reading performance in the product management phase in which management on a per-product basis is required and the work management phase in which management on a per-managed-point basis and in units of multiple managed points is required, such as connecting points for piping and device adjustment points.
Furthermore, since information referenced or registered in the product management phase is different from information referenced or registered for each managed point, it is necessary to prepare separate RFID tags in order to manage information in association with individual RFIDs. In addition, though RFID tags are sometimes discarded after product management ends, since they respond over a long distance, if they are discarded with their long-distance communication function maintained, they can cause misrecognition when a new product for management is read.
The present invention has been made in view of such circumstances and has an object of providing an RFID tag and a construction site management system and management method using the same that can efficiently implement product management until products manufactured at a factory, such as construction materials and equipment for installation, are used at a construction site as well as work management at the time when such products are used at the construction site, and that also suppress management errors.